By nightfall, all five bodies had been laid out side by side on the quay.
The battle to save them had been frantic and it broke the hearts of the rescue workers to see that, despite their best efforts, their lives could not be saved.
The gardai had wept, the fire personnel and RNLI lifeboat volunteers all shedding tears for the family laid out before them on what had been a beautiful sunny spring day on the banks of Lough Swilly.
"It was harrowing. It was harrowing to see the bodies laid out on the ground.
"It was hard to see the gardai crying and they with young children of their own. To see the five hearses pulling up there to take away the bodies."
Mark Barnett, brave coxswain with the RNLI, stood at the pier in Buncrana and tried to force back tears as he recalled the traumatic horror of what had happened here less than 24 hours ago.
At one point, ambulance workers were performing CPR simultaneously on four of the victims taken from the cold, grey waters of Lough Swilly on the quayside. Someone even had to race to the local Supervalu to get another defibrillator because they simply didn't have enough equipment.
How could they have had, Mark asked simply.
Nobody could have ever prepared for such a thing. No training could ever suffice.
It had been a beautiful sunny day along the majestically jutting and swooping coastline of the Inisowen peninsula. The RNLI had been taking part in a helicopter exercise on Lough Swilly and the volunteers had just wound up a tough but satisfactory day's work.
Mark had hopped into his car for the short two-mile journey home but had only gone out the road when his pager pinged. The message was terse. A car had gone off the pier in Buncrana, it said. Children and adults in the water.
"It must've happened seconds after I left," he said, explaining that in normal circumstances volunteers would have been able to devise a plan en route to an accident.
This time, there was no time to plan for what they would have to deal with.
He struggled to describe what they had seen, the light behind Lough Swilly fading, as eye witnesses on the pier screamed that there were people still in the car that had disappeared under the water, 12 metres deep.
The baby, little Rioghnach-Ann had just been taken from the car. A crew member dived down. The doors of the car were locked but the boot was open. He was able to extract two children - one of the boys and Jodie Lee (15).
"As we were getting them, we passed them over to the fire brigade," he said. "It was harrowing. To have a family, so many people, gone like that over a very simple thing to go wrong."
All day long, a pilgrimage of people - including young mothers from Derry clutching their own children by the hand - sorrowfully wound their way down to the pier at Buncrana to gaze silently into the waters.
One young mother, Sarah Harper, had come from Derry to pay her respects, while Susan Kelly and Brigid Doorley, also from Derry, spoke in hushed tones.
Susan said she was a "far-out relation" of the family, through her great-grandmother. All Derry people come to Buncrana, she said, explaining why it had been a natural day out for Sean McGrotty, his mother-in-law Ruth Daniels, sister-in-law Jodie-Lee (15) and his own children, Mark (12), Evan (8) and baby Rioghnach-Ann.
"This'd be our first stop. This is Donegal to us," said Susan. It's barely a 10-minute drive and when the weather is fine "it's as good as going foreign," she said.
Bouquets were left at three separate points along the pier. In a devastatingly poignant tribute to the three children whose lives had been snuffed out during their Easter holidays, a little blue tin of sweets in the shape of a bunny rabbit (inset left) had been placed where the tragedy had happened.
The tyre marks of Sean McGrotty's Audi Q7 were still plainly visible on the green algae of the slipway, an indicator of how he wrestled with the car in the helpless battle to save his family.
This was not the first time Buncrana has been plunged into mourning. Thirty years ago, musician Phil Coulter's sister Cyd, a social worker, was killed along with a man she was attempting to counsel when he drove them both off the same Donegal pier.
In August 1998, the Omagh bombing claimed three Buncrana children - Oran Doherty (8), Sean McLoughlin (12) and James Barker (12) had been on a day trip to the town.
Six years ago, the most devastating road crash in the history of the State occurred on the outskirts of Buncrana, when eight men were killed after an overloaded Volkswagen Passat smashed into an oncoming car.